pinctrl: mcp23s08: fix irq setup order

When using mcp23s08 module with gpio-keys, often (50% of boots)
it fails to get irq numbers with message:
"gpio-keys keys: Unable to get irq number for GPIO 0, error -6".
Seems that irqs must be setup before devm_gpiochip_add_data().

Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Mastykin <mastichi@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-mcp23s08.c

@@ -890,16 +890,16 @@ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
 			goto fail;
 	}
 
-	ret = devm_gpiochip_add_data(dev, &mcp->chip, mcp);
-	if (ret < 0)
-		goto fail;
-
 	if (mcp->irq && mcp->irq_controller) {
 		ret = mcp23s08_irq_setup(mcp);
 		if (ret)
 			goto fail;
 	}
 
+	ret = devm_gpiochip_add_data(dev, &mcp->chip, mcp);
+	if (ret < 0)
+		goto fail;
+
 	mcp->pinctrl_desc.name = "mcp23xxx-pinctrl";
 	mcp->pinctrl_desc.pctlops = &mcp_pinctrl_ops;
 	mcp->pinctrl_desc.confops = &mcp_pinconf_ops;